Recent developments and applications for optical full field strain measurement using ESPI and DIC

Abstract

Optical measurement techniques for full-field analysis of deformation, strain and vibration are commonly used in various fields of mechanical engineering. The focus of this presentation is on the recent developments and applications of the Electronic Speckle Pattern Interferometry (ESPI) and Digital Image Correlation (DIC) technique. The full-field function allows an easy understanding of processes and designs under various conditions and their optimizations. We present a brief overview about recent applications of ESPI for the determination of static strain in composite and inhomogeneous materials and the use of the technique for optimization of the design of components in automotive applications. DIC techniques have proven to be a flexible and useful tool for deformation analysis. Modern algorithm and computer allows the calculation of the full-field three-dimensional displacement and strain in real-time. This information can be converted to an electronic analog signal and be used for the real-time monitoring of the test. Using High Speed cameras the DIC technique can be applied to vibration problems and a high resolution in the temporal domain can be achieved. Different types of loading, like harmonic, shock or noise excitation, are applicable.